State Street also created SHE, an index designed to track gender diversity in corporations.

The statue was originally placed as a publicity ploy in honor of International Women's Day on behalf of McCann and State Street Global Advisers.

Di Modica, 76, told reporters Wednesday that the girl changes the positive message of the bull sculpture, which is "a better America and a better world".

Aside from potentially violating the trademark and copyright Di Modica owns on "Charging Bull" - State Street has shown the bull and "Fearless Girl" together on marketing materials - his lawyers say the new bronze also violates commercial laws.

Di Modica isn't so quick to jump on the bandwagon.

Certain tweets were more explicit, saying the bull statue already had implications of hyper-masculinity and a statue of a little girl staring it down had not created that impression.

Sculptor Arturo Di Modica, left, listens to attorney Norman Siegel, upper right, at his law offices in New York Wed., April 12, 2017, as Di Modica and his attorneys announced at the news conference that he's challenging city officials who issued a permit for "Fearless Girl", a bronze statue that faces the bull sculpture on the same cobble stone island in the street, and has drawn worldwide attention.

His attorneys argue that "Fearless Girl" is merely a derivative piece of Di Monica's "Charging Bull". The two bronze sculptures stand, face-to-face, in the heart of Wall Street in New York's Bowling Green Park.

"The girl is standing there like this in front the bull, saying, 'Now, what are you going to do?'" the artist said at a press conference, holding his hands on his hips like "Fearless Girl".

The Washington Post reported that Di Modica "doled out sharp criticism" of the statue and said it was not art but a "publicity stunt". His lawyers say they're down to sort this one out with New York City and the firm which installed Fearless Girl outside of court, but they're not dismissing the possibility of further legal action. After a public outcry from its subsequent impounding and removal by the city of NY, it was moved into its current position with an official ceremony in 1989.

The 3,200kg bull itself originally appeared as guerrilla art, installed unofficially in front of the New York Stock Exchange by Di Modica in 1989 and meant to convey the fighting spirit of the United States and of New York.

Twenty-five percent of the largest 3,000 U.S. companies have no female directors, State Street noted at the time.